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Re: Cosmic rays?? [7:71402] posted 06/26/2003
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The only thing close to your story is the comment from Robert and Barbara
Thompson in _PC Hardware In A Nutshell, 2e_ where they comment that on a
device used as a server or any other PC that needs a large RAM, they always
use ECC memory (Error Checking and Correction) because (honest!) cosmic rays
do strike.

Quote:
One common cause of "flipped bit" memory errors is, believe it or not,
cosmic rays. The more memory you have installed, the more likely it is that
a random cosmic ray will impact one of the memory cells in a chip on your
system, causing the contents of that cell to flip from binary zero to a one
or vice versa. We don't pretend to understand this issue, but we've been
told by memory experts that for systems with 512MB of RAM, using ECC versus
non-parity memory is about an even trade-off in terms of extra cost and lost
performance versus the likelihood of memory errors. For systems with 768MB+,
we use ECC memory exclusively.
End quote (pp201-2).

However ... that could also be a Real Convenient Excuse. Do you have any
kind of other experience with the people who said this (like, are they
naturally FUD-prone)?

Annlee

""Juan Carlos Perez""  wrote in message
news:200306260246.h5Q2k8iI023881@xxxxxxxxxxxxxxxxx
> We have a Cisco  VIP card plugged into a 7500 router. Every once in a
while
> the card  just stops working and sometimes it gets stuck so hard that we
> have to reload the microcode. The last we did that, the router crashed and
> had to be reset (Ugly!). Well, it gets worse. After having to convince the
> guys at the local Cisco office to help us in this issue, they came to our
> facilities and began their analysis. To make a long story short, they told
> us that these problems were caused by cosmic rays! We almost fainted!
Cosmic
> rays!
> Has anybody around here ever heard of this problem in this combo?  Let me
> tell you this router is not installed in a spaceship or something like
that,
> it4s just an ordinary datacenter.
> Any ideas about what the real problem might be?
>
> P. S. The router is using a recent version of IOS (newer than 12.1) and
has
> been patched as per the Cisco site.
>
> Thanks a lot for any advice on this issue.




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